Step 1: Place ngrok in /usr/local/bin/.
Step 2: Get authtoken from ngrok website, then add it to /etc/ngrok/ngrok.yml.
Step 3. Modify your own configrations in /etc/ngrok/ngrok.yml.
Step 4: Add ngrok.service to /lib/systemd/system/.
Step 5: Start ngrok service by typing:
systemctl enable ngrok.service
systemctl start ngrok.service
or just execute install.sh on Linux x64 platform.
chmod +x install.sh
./install.sh <your_authtoken>